Bug: Warning: React does not recognize the fetchPriority prop on a DOM element [React 18.3.1]

[martabitbrain]

React version: 18.3.1

This bug may be related to #28946 .

Steps To Reproduce

1. Create an image tag with fetchPriority="high" attribute (camelCase)
2. Create an image tag with fetchpriority="high" attribute (lowercase)

Link to code example: https://codesandbox.io/p/sandbox/quiet-haze-5hkscx

The current behavior

Output: (fetchpriority attribute looks ok!)

<img fetchpriority="high" src="https://dummyimage.com/200x64/b000b0/fff&text=fetchPriority">
<img fetchpriority="high" src="https://dummyimage.com/200x64/00b075/fff&text=fetchpriority">

Warning:

Warning: React does not recognize the `fetchPriority` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `fetchpriority` instead. If you accidentally passed it from a parent component, remove it from the DOM element.

The expected behavior

The same output, but no warning.

[eps1lon]

Duplicate of #27233. Fixed in Canary release channel and once React 19 becomes stable.

[martabitbrain]

Sorry, I didn't notice.

[MKSisti]

it's Nov now and React 19 is still not stable sadly, can we get the fix rolled for 18.x.x @eps1lon 🙏